Lecture on Empirical and Molecular Formulas

These flashcards cover key concepts related to empirical and molecular formulas, including definitions and essential relationships in chemistry.

Empirical Formula

The simplest whole-number ratio of elements in a compound.

Percentage Composition

Expressing the amount of an element in a compound as a percentage by mass.

Molar Mass

The mass of one mole of a substance, typically expressed in g/mol.

Avogadro's Number

6.022 x 10²³, the number of particles in one mole of a substance.

Standard Temperature and Pressure (STP)

Standard conditions for measuring gases: 0 degrees Celsius and 1 atm pressure.

Ideal Gas Law

PV = nRT, a relation between pressure (P), volume (V), moles (n), gas constant (R) and temperature (T).

Subscripts in Empirical Formula

The numbers in an empirical formula that indicate the ratio of atoms of each element.

Conversion of Mass to Moles

Using the molar mass of an element to convert grams of that element into moles.

Empirical vs Molecular Formula

Empirical formula gives the simplest ratio of elements, while molecular formula shows the actual number of atoms.

Volume of a Gas at STP

The volume occupied by one mole of an ideal gas at STP is 22.4 liters.